I have put in some work on Mob-Arena's backend code today. There's little actual change gameplay-wise, though, at least for now. We are planning on a huge update some time very soon that will do nothing short of totally revamping the server, and this new Mob-Arena rework will be one part of it, so stay tuned.

NEW FEATURES

Added many new mobs that utilize Libs' Disguises plugin.

Fixed a display bug on Husks, Strays, Wither Skeletons and Elder Guardians which caused them to display as their normal counterparts.

Added an extensive system of over-time spawns and ability to put multiple spawn groups of mobs into a single wave. This allows us to fine-tune exactly when and where the mobs spawn, and even allow us to create bosses with nonstop-spawning minion mobs in the background.

For now we have tweaked the Nether map to incorporate these new features as a proof-of-concept. Feel free to try it out, or wait for our big updates to roll out in a few days. As always, please report feedback and bugs on our forums.

Edit 3/3:

We have tweaked the Starter, Nether, Suburb and Infection maps. They are now much more different than before and takes advantage of the new Mob-Arena features. Be sure to check them out!

The number of waves now depends on the map, and they are the same as the original Mob-Arenas from before they all got normalized to 100/50 waves.

The time between waves now also depends on the map.

Armored mobs are now very rare, and their armor level no longer depends on the difficulty.

In return, most mobs now have double health.

Mobs in a single wave no longer spawn all at once. Instead, they spawn over a few seconds. This reduces strain on the server's hardware and also makes it more forgiving to be in the open.

Boss waves will now spawn minions nonstop (but rather slowly) so long as the boss is still alive. The type of minion depends on the boss.

The bosses now delay 10 seconds before spawning to give players time to prepare and allow a few minions to spawn in first.

Added many types of new mobs, including disguised mobs which look like animals. One of the bosses is even a pig!

Revamped visuals on boss abilities!

A new ability: Laser!

The rest of the map changes will follow up soon.

The Mob-Arena lobby has also gotten a visual revamp. Now, the lobby shows the icon of each map in the voting menu, the number of waves, and a good estimate of the map's difficulty.

We have also removed Easy mode from the Mob-Arena lobby because it is rarely played, but you can still vote for it if you choose to manually join a match.